Joseph Ratzinger, following the interpretation of Saint Augustine, says that Mary and Martha are not simply representative of two types of life, the contemplative and the active, but rather the two phases of every Christian life, the way and the end. Mary represents the end, Martha the way. They represent two lives, the present life and the future life. In this life, the way to achieve union with Christ, which is the end for which we live, is not simply the Platonic ascending mode of study and pure contemplation but also in the descending mode of the Incarnation of preaching and doctrinal instruction. It is by means of union with and service to the Body of Christ, the Church, that one achieves final union with Christ the Head, achieved perfectly only at the end of this life.
Joseph Ratzinger, "The Church in the Piety of Saint Augustine" (1961) in Das neue Volk Gottes: Entwürfe zur Ekklesiologie, Düsseldorf, 1969, 24-48.
What Ratzinger mentions but does not emphasize in that essay on Augustine on Mary and Martha is the supreme importance of the unum necessarium, to sit at the feet of Jesus and listen to Him, which is the point of the Gospel in that encounter, the primacy of union with the Lord. What matters above all is the end, to do all things for Christ and for heaven. The meaning of all our activity in the Church and in the world is to do it all at the service of Christ and of the Gospel and the salvation of souls, divine union, holiness for oneself and for others.
All of this is brought out very well in the Baltimore Catechism: Why did God make you? God made me to know Him and to love Him and to serve Him in this life, so as to be happy with Him forever in the next. The purpose of all of our activity is union with God, here and hereafter.